S. Matsui

Hydrolysis of (ligno)cellulosic materials under sulfidogenic and methanogenic conditions

A Biochemical methane potential (BMP) test and Serum Bottle Reactor (SBR) test were used to compare hydrolysis (mineralization) of lignocellulosic materials under sulfidogenic and methanogenic conditions. Lignocellulosic carbon mineralization under sulfidogenic conditions was found to be more than 2 times higher than under methanogenic conditions. The percentages of lignocellulosic carbon mineralized under methanogenic condition were 18.0% and 10.71% while under sulfidogenic conditions 36.69% and 27.44% for office paper and newspaper, respectively. Although a poor linear relationship between the percentage of carbon mineralization and percentage lignin content was observed, but in general a decrease in mineralization of lignocellulosic carbon was observed with the increase in lignin content. A method based on selective inhibition of microorganism activity, by 3% toluene, was used to measure the initial rate of lignocellulosic material mineralization and the accumulation of mineralized products (i. e. sugars). Sugars linearly accumulated over time and the accumulation rates of glucose and xylose were calculated. The accumulation rates of glucose under methanogenic condition were 1.302, μM/g-dry wt hr and 0.004, μM/g-dry wt hr while under sulfidogenic condition they were 2.624, μM/g-dry wt hr and 2.279 μM/g-dry wt hr for offce and newspaper, respectively.